4.7 Article

Projecting future nitrogen inputs: are we making the right assumptions?

Journal

ENVIRONMENTAL RESEARCH LETTERS
Volume 17, Issue 5, Pages -

Publisher

IOP Publishing Ltd
DOI: 10.1088/1748-9326/ac6619

Keywords

nitrogen budget; nitrogen use efficiency; projection scenarios; technology and management practices; crop mix; yield response functions

Funding

  1. National Science Foundation [CBET-2047165, CBET-2025826]
  2. National SocioEnvironmental Synthesis Center (SESYNC)

Ask authors/readers for more resources

This study projected nitrogen inputs to 2050 by developing and testing three approaches. The results showed that considering diminishing returns in yield response functions led to higher nitrogen inputs. The study suggests that when investigating future nitrogen budgets, a range of projection assumptions need to be carefully explored.
Global use of reactive nitrogen (N) has increased over the past century to meet growing food and biofuel demand, while contributing to substantial environmental impacts. Addressing continued N management challenges requires anticipating pathways of future N use. Several studies in the scientific literature have projected future N inputs for crop production under a business-as-usual scenario. However, it remains unclear how using yield response functions to characterize a given level of technology and management practices (TMP) will alter the projections when using a consistent dataset. In this study, to project N inputs to 2050, we developed and tested three approaches, namely 'Same nitrogen use efficiency (NUE)', 'Same TMP', and 'Improving TMP'. We found the approach that considers diminishing returns in yield response functions ('Same TMP') resulted in 268 Tg N yr(-1) of N inputs, which was 61 and 48 Tg N yr(-1) higher than when keeping NUE at the current level with and without considering changes in crop mix, respectively. If TMP continue to evolve at the pace of past five decades, projected N inputs reduce to 204 Tg N yr(-1), a value that is still 59 Tg N yr(-1) higher than the inputs in the baseline year 2006. Overall, our results suggest that assuming a constant NUE may be too optimistic in projecting N inputs, and the full range of projection assumptions need to be carefully explored when investigating future N budgets.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available